The aims of this project are to delineate the mechanism by which oxidation causes changes in lens transport systems. Three model systems will be used to examine transport. H2O2, hyperbaric O2 and photo-oxidation. Na/K ATPase, Ca ATPase and amino acid transport will be investigated. The impact of oxidative insult to the pump systems upon important metabolic parameters such as ATP, NAD(P) and NAD(P)H, lactate and glutathione will be examined. The model systems will be compared to human cataract to ascertain similarities in the pattern of cataract development. The origin of aqueous H2O2 and its relationship to ascorbate will also be investigated as well as initiation of a drug screening program to protect the lens membrane from oxidative insult.